The VASCO™ family of DLS particle size analyzers is the outcome of collaboration with the French Petroleum Institute (IFPEN). These systems are dedicated to the size characterization of nano-particles in complex medium without the need to dilute the sample.

Thanks to the special cell geometry setup (adjustable thin layer analysis), dark samples, as well as high concentration samples can be analyzed without dilution!

Conventional DLS is a powerful technique useful in characterizing dilute and transparent dispersions of nanoparticles. However, it becomes ineffective in dark media since the laser beam is absorbed by the sample which can induce an interfering effect. This phenomenon called "multiple scattering artifact" biases measurement results, when analyzing a concentrated samples. This phenomenon interferes with the correlation calculations and leads to underestimation of the hydrodynamic radius of particles.

Its capability to control the sample thickness limits further this artifact and strongly reduces the laser thermal effect. This allows very accurate measurements even in concentrated and dark dispersions.